Ps4 – make imported PS4 games work region free

According to this article:

In general, neither digital nor disc-based games will be region locked, but PlayStation recommends that all users purchase games at the region of their residence to guarantee the best overall experience and customer service. In certain instances, a software publisher may choose to region lock a game title for specific reasons, but Sony Computer Entertainment expects these instances to be uncommon.

This is just for the games however. DLC purchases appear to be a different story. If your Playstation Account is North American, and your game is from Europe, the North American DLC for that game will not work. As the article words it:

However, this does not apply to DLC (downloadable content). If you own a North American game, then you would need to purchase the North American DLC for that title in the North American PSN store with a North American PSN ID.

Bottom line, the games should work no problem. DLC you will have to be careful with.